Method for manufacturing semiconductor memory and method for manufacturing capacitor

Abstract

A method of manufacturing a semiconductor memory cell is provided. The semiconductor memory cell can include a memory cell transistor ( 10 ) and a capacitor. The capacitor can be formed in a groove ( 13 ) formed in an interlayer insulation film ( 12 ). The capacitor can have a lower electrode including a selective growth film ( 18 ) which may be selectively deposited on a lower electrode film ( 16 ). Selective growth film ( 18 ) can be a ruthenium film having a thickness of approximately 5˜10 nm and may serve as a buffer which may prevent lower electrode and a capacitor insulation film ( 20 ) from deterioration in integrity which could cause increased leakage currents.

What is claimed is:  
     
       1. A method for manufacturing a semiconductor memory having an array of memory cells, each memory cell including a memory cell transistor electrically connected to a capacitor, comprising the steps of: 
       forming a memory cell transistor on a semiconductor substrate followed by forming a first interlayer insulation film over a surface resulting after forming the memory cell transistor;  
       forming a groove for making the capacitor at a predetermined location in the first interlayer insulation film;  
       forming a lower electrode film over a surface resulting from forming the groove;  
       applying and processing a resist material so as to leave a resist film in the groove;  
       removing excess portions of the lower electrode film so as to leave the lower electrode film in the groove;  
       selectively forming a first metal film on the lower electrode film after applying and processing the resist material; and  
       forming a capacitor insulation film and an upper electrode film over a surface resulting from removing excess portions of the lower electrode film.  
     
     
       2. The method according to  claim 1 , further including removing the resist film after removing excess portions of the lower electrode film. 
     
     
       3. The method according to  claim 2 , wherein removing the resist film uses an oxygen plasma. 
     
     
       4. The method according to  claim 1 , further including the steps of: 
       forming a second interlayer insulation film over a surface resulting after forming the capacitor insulation film and the upper electrode film;  
       forming a bit contact hole by removing selected portions of the second interlayer insulation film and first interlayer insulation film to expose a source/drain region of the memory cell transistor;  
       forming a second metal film in the bit contact hole; and  
       forming bit lines on the second interlayer film so as to electrically connect a column of memory cells.  
     
     
       5. The method according to  claim 1 , wherein selectively forming a first metal film on the lower electrode film is carried out by means selected from the group consisting of chemical vapor deposition, physical vapor deposition, and a combination of chemical vapor deposition and physical vapor deposition. 
     
     
       6. The method according to  claim 1 , wherein the first metal film on the lower electrode film includes ruthenium. 
     
     
       7. The method according to  claim 1 , wherein the groove is cylindrical. 
     
     
       8. A method for manufacturing a semiconductor memory having an array of memory cells, comprising the steps of: 
       forming a memory cell transistor on a semiconductor substrate followed by forming a first interlayer insulation film over a surface resulting after forming the memory cell transistor;  
       forming a capacitor contact hole in the first interlayer insulation film to expose a first diffusion region of the memory cell transistor;  
       forming a capacitor contact electrically connected to the first diffusion region;  
       forming a second interlayer insulation film on the first interlayer insulation film;  
       forming a groove for making a capacitor at a predetermined location in the second interlayer insulation film;  
       forming a lower electrode film over a surface resulting from forming the groove;  
       applying and processing a resist material so as to leave a resist film in the groove;  
       removing excess portions of the lower electrode film so as to leave the lower electrode film in the groove;  
       selectively forming a first conductive film on the lower electrode film after applying and processing the resist material; and  
       forming a capacitor insulation film and an upper electrode film over a surface resulting from removing excess portions of the lower electrode film.  
     
     
       9. The method according to  claim 8 , further including removing the resist film after removing excess portions of the lower electrode film. 
     
     
       10. The method according to  claim 9 , wherein removing the resist film uses an oxygen plasma. 
     
     
       11. The method according to  claim 10 , wherein the capacitor insulation film comprises at least one of the materials selected from the group consisting of tantalum oxide, lead zirconium titanate, barium titanate, and strontium titanate. 
     
     
       12. The method according to  claim 11 , wherein the first conductive film on the lower electrode film includes ruthenium. 
     
     
       13. The method according to  claim 8 , wherein the memory cells are DRAM cells, the method further including the steps of: 
       forming a third interlayer insulation film over a surface resulting after forming the capacitor insulation film and the upper electrode film;  
       forming a bit contact hole by removing selected portions of the third interlayer insulation film, the second interlayer insulation film, and the first layer insulation film to expose a source/drain region of the memory cell transistor;  
       forming a second conductive film in the bit contact hole; and  
       forming bit lines on the third interlayer film so as to electrically connect a column of memory cells.  
     
     
       14. The method according to  claim 13 , wherein the groove is cylindrical. 
     
     
       15. A method for manufacturing a capacitor formed on a semiconductor substrate, comprising the steps of: 
       forming a first interlayer insulation film over a surface of the semiconductor substrate;  
       forming a groove for making the capacitor at a predetermined location in the first interlayer insulation film;  
       forming a lower electrode film over a surface resulting from forming the groove;  
       applying and processing a resist material so as to leave a resist film in the groove;  
       removing excess portions of the lower electrode film so as to leave the lower electrode film in the groove;  
       forming a conductive film on the lower electrode film after applying and processing the resist material; and  
       forming a capacitor insulation film and an upper electrode film over a surface resulting from removing excess portions of the lower electrode film.  
     
     
       16. The method according to  claim 15 , further including the steps of: 
       before forming the first interlayer insulation film, forming a second interlayer insulation film over a surface of the semiconductor substrate;  
       forming a capacitor contact hole in the second interlayer insulation film to expose a diffusion region in the semiconductor substrate; and  
       forming a capacitor contact electrically connected to the diffusion region.  
     
     
       17. The method according to  claim 15 , further including removing the resist film after removing excess portions of the lower electrode film. 
     
     
       18. The method according to  claim 17 , wherein removing the resist film uses an oxygen plasma. 
     
     
       19. The method according to  claim 15 , wherein the conductive film on the lower electrode film includes a ruthenium film having a thickness of between approximately 5 to 10 nm. 
     
     
       20. The method according to  claim 15 , wherein the groove is cylindrical.